Astronomers have discovered in the distant approaches of the solar system a previously unknown dwarf planet 2010 JO179 with an unusually inclined orbit, whose diameter is an impressive 900 kilometers, according to an article posted on the arXiv.org electronic library.
“This dwarf planet is unusually bright for typical inhabitants of the Kuiper belt, but its high inclination angle of more than 30 degrees made it difficult for our colleagues to find it earlier. Her discovery shows that the discovery of other dwarf planets will require very 'wide' sky surveys, covering not only the plane of the solar system, but also the regions above and below it,”said Michele Bannister of the University of Belfast (UK).
Parade of planets
In recent years, scientists have discovered several large dwarf planets and objects on the distant approaches to the solar system, clearly showing that "life" in it does not end behind the orbits of Neptune and Pluto, and that large celestial bodies continue to meet at farther distances.
So, in 2014, planetary scientists Chad Trujillo and Scott Shepard announced the discovery of "Biden" - plutoid 2012 VP113, moving away from the Sun at 12 billion kilometers, and in 2015 they discovered the dwarf planet V774104, moving away from the star even further. At the beginning of last year, hints of the existence of a giant "planet X" were found and the dwarf planet 2015 KH162 was found, the year on which lasts 500 years.
A year ago, Bannister and her colleagues broke the record for Trujillo and Shepard by discovering the small planet 2015 RR245, a plutoid supposedly 700 kilometers in diameter, moving away from the Sun by a record 120 astronomical units, or 18 billion kilometers.
Bannister and her colleagues unexpectedly discovered another large and rather distant dwarf planet beyond the orbit of Neptune, studying archived images and data collected by the automated Pan-STARRS 1 telescope, designed to search for asteroids, comets and other small celestial bodies.
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Scientists drew attention to the fact that this telescope "looked" not only at the ecliptic plane, the "pancake" of the solar system, inside which virtually all its planets live, except Pluto, but also at rather large areas above and below it. Many comets and asteroids were thrown here in the distant past, orbiting today around the Sun in an orbit inclined in relation to the ecliptic.
Jupiter, Saturn, Uranus and Neptune, as astronomers believe today, did not appear in their current orbits, but at the distant approaches to the solar system, from where they migrated towards the sun in the first moments of their life. These "planetary migrations" should have thrown dozens of large dwarf planets outside the ecliptic, and caused them to revolve around the Sun like comets and asteroids from the inner solar system.
Younger "brother" of Pluto
Guided by this idea, scientists analyzed and specially reformatted the data and images from the Pan-STARRS 1 database in the hope of finding similar dwarf planets on them. This was not easy to do, since this telescope periodically switches to new areas of the night sky, because of which it can only track the movement of the slowest dwarf planets.
Despite these limitations, astronomers quickly discovered the first such dwarf planet, 2010 JO179, whose size allows it to enter the twenty largest "cousins of Pluto."
It moves in an unusually elongated orbit, whose closest point to the Sun is located at a distance of about 39 astronomical units from the star, or 5.8 billion kilometers, and the farthest - at a distance of 117 astronomical units (17.5 billion kilometers).
The high brightness of this dwarf planet allowed scientists not only to measure its dimensions - about 600-900 kilometers, but also to determine its shape, calculate the length of the day on it and reveal some features of its surface.
It turned out that 2010 JO179 rotates around its axis rather slowly for a dwarf planet - a day lasts about 30 hours, and one of its sides is darker than the opposite, like Pluto and its bright "heart" surrounded by dark mountains. In its shape, this dwarf planet looks more like a ball than an ellipse or any other irregular shape.
The most interesting side of this planet, as the researchers note, is not its physical properties or size, but its orbit. As their calculations show, it is in orbital resonance with Neptune - during the time that 2010 JO179 spends for five orbits around the Sun, the giant planet orbits the star exactly 21 times. Accordingly, the year on the "younger brother" Pluto lasts about 700 years.
The existence of such a connection between Neptune and 2010 JO179, according to Bannister and her colleagues, may not be a coincidence. Scientists believe that the orbit of this dwarf planet may conceal traces of Neptune's migrations in the distant past. Therefore, the search for other planets with a similar orbit could help astronomers understand how the Earth and other planets of the solar system originated, in which the giant planets played a key role.
Unfortunately, the discovery of this planet, as Bannister explained to RIA Novosti, will not help astronomers quickly localize the position of the mysterious "planet X" - it is too far away for 2010 JO179 and similar dwarf planets to interact with it.